WTPA42 PHFO 230909
TCDCP2

HURRICANE NEKI DISCUSSION NUMBER  19
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
1100 PM HST THU OCT 22 2009

HURRICANE NEKI IS SLOWLY WEAKENING AS STRONG SOUTHWESTERLY SHEAR
CONTINUES TO IMPACT THE SYSTEM. INITIAL INTENSITY HAS BEEN LOWERED
TO 80 KT AS THE LATEST INFRARED SATELLITE PRESENTATION SHOWS
WARMING CLOUD TOPS AND SHRINKING AREAL EXTENT OF THE DEEPEST
CONVECTION. SATELLITE FIXES FROM CPHC AND JTWC ARE AT 4.5 AND SAB
IS AT 5.0...CONFIRMING THE GRADUAL WEAKENING TREND. AFTER RE-BESTING
THE 00 UTC POSITION WITH ADDITIONAL MICROWAVE DATA...THE 06 UTC
INITIAL POSITION IS CLOSELY IN LINE WITH AGENCY FIXES AND SHOWS THE
SYSTEM MOVING NORTH-NORTHEAST A BIT SLOWER THAN THE PREVIOUS 
FORECAST.

MODELS ARE IN GOOD AGREEMENT WITH A SLOW NORTH-NORTHEAST MOTION IN
THE SHORT TERM. AFTER 72 HOURS...MODEL CONSENSUS INDICATES AN 
ACCELERATION TOWARDS THE NORTHEAST AS NEKI IS PICKED UP BY A TROUGH 
IN THE WESTERLIES. MODEL GUIDANCE SHOWS A SIGNIFICANT SLOW DOWN IN 
THE MOVEMENT OF NEKI THROUGH 72 HOURS. THE CURRENT FORECAST IS 
SLOWER THAN THE PREVIOUS PACKAGE AND SLIGHTLY AHEAD OF MODEL 
CONSENSUS.
 
STRONG SOUTHWESTERLY SHEAR WILL CONTINUE TO IMPACT NEKI OVER THE NEXT
SEVERAL DAYS AND THUS GRADUAL WEAKENING WILL CONTINUE.  THE
WEAKENING ACCELERATES AFTER 48 HOURS AS NEKI REACHES COLDER WATERS
AND SHEAR INCREASES. BEYOND 72 HOURS...NEKI WILL RAPIDLY WEAKEN AND 
BECOME EXTRATROPICAL AS IT IS CAUGHT UP IN THE WESTERLIES. NEKI MAY 
NOT EVEN LAST THAT LONG...AS SOME MODELS LOSE THE STORM BY 96 HOURS. 
HAVE REMOVED THE 120 HOUR POSITION AND PUSHED THE EXTRATROPICAL 
TRANSITION TO 96 HOURS.
 
ON ITS CURRENT TRACK...NEKI WILL BE IMPACTING THE PAPAHANAUMOKUAKEA
NATIONAL MONUMENT NEAR FRENCH FRIGATE SHOALS OVERNIGHT AND
FRIDAY...AND A HURRICANE WARNING REMAINS FOR THE MONUMENT FROM
NIHOA ISLAND TO MARO REEF. LARGE SWELLS FROM THE SOUTH WILL BUILD
AND CONDITIONS WILL CONTINUE TO DETERIORATE ACROSS PORTIONS OF THE
WARNING AREA OVERNIGHT...WITH SEAS GREATER THAN 20 FT AND SURF UP 25
FT EXPECTED.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      23/0900Z 22.3N 165.9W    80 KT
 12HR VT     23/1800Z 23.4N 165.6W    75 KT
 24HR VT     24/0600Z 24.9N 165.0W    70 KT
 36HR VT     24/1800Z 26.7N 164.1W    65 KT
 48HR VT     25/0600Z 28.4N 163.0W    60 KT
 72HR VT     26/0600Z 31.7N 160.8W    45 KT
 96HR VT     27/0600Z 36.9N 157.8W    30 KT...EXTRATROPICAL
 
$$
FORECASTER TANABE/BRENCHLEY